U.S. Pat. No. 4,243,586, issued Jan. 6, 1981 to Chao and Varma discloses various 17-spirodihydrofuranone androstenes having the partial structural formula ##STR2## wherein R.sub.a is bromine, chlorine or fluorine; R.sub.b is alkyl, aryl or arylalkyl; and R.sub.c is hydrogen, .alpha.-methyl, .beta.-methyl, hydroxy or a conventional hydrolyzable ester thereof. The steroids have antiinflammatory activity.
U.S. Pat. No. 3,757,009, issued Sept. 4, 1973 to Anner discloses various 17-spirodihydrofuranone androstenes having the partial structural formula ##STR3## wherein R.sub.d is hydrogen, lower alkyl, or aralkyl and R.sub.e is hydrogen, methyl, free or esterified hydroxyl or .beta.-halogen. The steroids have antiinflammatory activity.
U.S. Pat. Nos. 4,091,036, issued May 23, 1978, 4,094,840, issued June 13, 1978, 4,133,811, issued Jan. 9, 1979, and 4,146,538, issued Mar. 27, 1979, each discloses androstene intermediates having the partial structural formula ##STR4## wherein R.sub.f is alkyl or aryl, and both R.sub.f groups are the same.